Anyone know what vcml/vcmr should be ? The datasheet says "normally connected to vss" and it says that vss1-4 are connected to gnd, so vcml/r should be 0V ? There's only one reference to it that I can find.

The fact I can get noise of various kinds indicates to me that the analogue stage is working, and that it is the digital side that has a fault. Nonetheless, I've been over everything on this DAC several times now and found no fault.

I've spent over 10 hours debugging it and I can do no more. I have no clue why it doesn't work. There are hi-res photos on my blog - better than this site will allow - just click on the photo. www.myl8test.wordpress.com/audio/ak4399-dac/ The photo looks like pin1 and 2 are bridged with solder but actually that is not the case - funny angle or lighting or something.

Haha... yeah, that old trick was new to me ! Every DAC I've played with just started playing music as soon as it got the i2s connected.

I found my cat6 cable is the fault, not the cm6631. I've never had a cat cable fail on me before either.

Also, with the cm6631, no reset is necessary, it works immediately, so only the wolfson wants a reset. I'll have to look into why.

The DAC sounds good, but as Diyinhk says, the mids can be a little strident with the wrong op amps. So, op amp rolling once again. Since I'm going to use this to drive headphones, I have LM7321 in the second stage, and at the mo, I'm listening to ad8597 in the first stage. The trick is to get sets that suit the headphones - HD650 and PXC250 - rather than amps and speakers.

Thanks for the kind words about the blog - man, its time consuming getting it set up but now it is easy enough to navigate and add extra stuff too so, yeah... a start ! I'm now even more impressed with yours - that's got to have taken ages to get it looking that good.

Another update is on the blog, but briefly, I tried adding a ferrite and using cfb. It either didn't work (oscillation) or worked but didn't sound as good as LM7321. I use opa827 in the first stage, but NE5534 are surprisingly nice too, and soooo cheap. This could be a real bargain DAC with the right choice of parts.

The last thing to do is solder the vias, and add a receiver. I found an SRC4392 so I thought I'd give it a try. It looks mediocre but the output I2S lines haven't been messed with so it could sound okay.